Re: mistake about the cpufreq?

Re: mistake about the cpufreq?

[俞颐超]

On Fri, Jul 1, 2011 at 4:00 PM, 俞颐超 <yyc1992@gmail.com> wrote:
> The following is what I get when I run the command in
> /sys/devices/system/cpu/cpu0/cpufreq
>
> $ sudo grep "" *
> affected_cpus:0
> bios_limit:800000
> cpuinfo_cur_freq:2800000
> cpuinfo_max_freq:2801000
> cpuinfo_min_freq:800000
> cpuinfo_transition_latency:10000
> related_cpus:0 1
> scaling_available_frequencies:2801000 2800000 2133000 1600000 800000
> scaling_available_governors:conservative ondemand userspace powersave
> performance
> scaling_cur_freq:800000
> scaling_driver:acpi-cpufreq
> scaling_governor:performance
> scaling_max_freq:800000
> scaling_min_freq:800000
> scaling_setspeed:<unsupported>
>
> The problem is basically the scalings is different from cpuinfos. It
> appears when I unplug the power and still there when I have repluged
> the power.
> Does any know what probably the problem is and where can I look for
> more detail information.
>
> some basic info about my computer
>
> $ uname -a
> Linux yuyichao-PC 2.6.39-ARCH #1 SMP PREEMPT Mon Jun 27 21:26:22 CEST
> 2011 x86_64 Intel(R) Core(TM)2 Duo CPU T9600 @ 2.80GHz GenuineIntel
> GNU/Linux
> (The kernel version should be 2.6.39.2)
>
>
> Thanks.
>
> Yichao
>

So after reading the files in cpu-freq/, I saw it was mentioned in
user-guide.txt that the scaling_ ones is what the kernel thinks the
freq is and cpuinfo is the actual freq.
y can these two be different?

Re: mistake about the cpufreq?

[Matthew Garrett]

On Fri, Jul 01, 2011 at 09:17:08PM -0400, 俞颐超 wrote:

> So after reading the files in cpu-freq/, I saw it was mentioned in
> user-guide.txt that the scaling_ ones is what the kernel thinks the
> freq is and cpuinfo is the actual freq.
> y can these two be different?

Many systems don't have independently clockable cores. In that case the 
cpu will run at the speed of the highest clocked core.

-- 
Matthew Garrett | mjg59@srcf.ucam.org